Europe's central banker disappointed investors today after he refused to bow to pressure for an accelerated bond-buying programme to alleviate pressure on ailing eurozone economies and the beleaguered banking sector.

European Central Bank president Jean-Claude Trichet said at a press conference that he would continue to provide banks with unlimited liquidity well into next year. However, he made no commitment to increase the pace of bond-buying through the ECB's ongoing Securities Market Programme (SMP).

The ECB board agreed that it would send the wrong signal to proceed with the phasing-out of unlimited liquidity measures for the eurozone banks now, as it had been expected to do until recently. However, it appeared that this was not a unanimous decision.

Trichet said the bank had decided to conduct three-month liquidity operations in January, February and March "with full allotment".

Investors took Trichet's comments as a rejection of the analysts and economists who have called for the ECB to support the banking sector and the wider eurozone economy in a similar manner to the US Federal Reserve. The Fed agreed last month to pump $600bn into the US economy to ease concerns that a massive de-leveraging by US banks would stall the economy.

Trichet said he would not support a similar quantitative easing plan to support the likes of Portugal and Spain, despite growing demands from investors for fresh anti-crisis measures including Fed-style government bond-buying on a much larger scale.

"The Securities Market Programme is ongoing, I repeat … ongoing," Trichet said after the ECB's monthly policy meeting left interest rates at 1%. "I won't comment on the observations of market participants," he added.

Howard Archer, chief European and UK economist at IHS Global Insight, said the ECB had only announced "the minimum of what was expected or hoped for by the markets".

"At least, though, the ECB has left the door open to stepping up its bond purchases markedly," Archer added.

The yield, or effective rate of interest, on Spanish, Portuguese and Irish 10-year government bonds fell today, bringing some relief to the peripheral members of the eurozone. The gap between the cost of their borrowing and the cost of Germany's borrowing, a widely watched benchmark in the market, also fell.

One report claimed that the ECB had been buying up Irish and Portuguese debt in the financial markets today, helping to push yields lower.

"More purchases needed"

The ECB started purchasing bonds through the SMP in May and has so far spent €67bn (£57.7bn), most of it during the first three weeks of the programme.

Analysts say the ECB may well have to expand the SMP soon if the eurozone debt crisis pushes Portugal and Spain towards seeking bailouts, following the example of Ireland and Greece. "We continue to look for €100bn of purchases by the beginning of next year, including Spanish securities," RBS economist Jacques Cailloux said in a note to investors.

Others foresee much larger interventions: Evolution Securities strategist Elisabeth Afseth said there could be a €1tn-€2tn euro bond-buying programme.

Debate will have been heated in the policy meeting.

Axel Weber, the president of Germany's central bank and a member of the ECB's governing council, has made his distaste for the programme clear and called for it to be scrapped in October, saying it had failed to calm bond markets.

Trichet said there had been a consensus within the ECB to keep liquidity flowing and that an "overwhelming majority" were in favour of continuing the bond-buying programme in its present form. There was no mention of unanimity.